一种用于半导体封装的焊球的制备方法

本发明提出一种用于半导体封装的焊球的制备方法，包括以下步骤：a.采用镍-钒合金和浮脱工艺，在晶片上制备凸点下金属层和分别在凸点下金属层的相对侧处连接的长方形回流引导金属层；b.采用制备直径在75微米至350微米的焊球的印刷模板，所述印刷模板具有比凸点下金属层和回流引导层大的矩形开孔；c.使用印刷机，通过印刷模板在已经制备了凸点下金属层和回流引导金属层的晶片上印制焊膏；d.根据焊膏材料要求，在一定温度下熔化和回流焊膏来形成焊球。这样提高了模板印刷技术制备焊球的工艺控制性，减小了焊球间距，提供了用于不同尺寸和材料的，具有可靠性的倒装焊焊球。The invented technique of preparing solder ball for encapsulating semiconductor includes following steps: preparing metal level and back flow leading metal level under salient point by using technique of nickel-vanadium alloy and float pulling off technique; designing and preparing printing template based on size of solder ball and technological requirements; printing soldering paste on chip by using printing machine; based on requirement of soldering paste material, forming solder ball under certain temperature by back flow. The invention raises possibility of technical control for preparing solder ball through template printing technique, reduces space between solder balls and provides reliable solder ball for upside down mounting solder in different sizes and materials.